The vagina is a musculomembranous tubular organ extending from the uterine cervix to the exterior of the body. The vaginal canal is about 9 or 10 cm long. Its lumen is generally quite small, and the walls that surround it are usually in contact with each other. Various are the organic fluids which pass through the vaginal canal during the female lifetime, such as blood, vaginal secretion fluids, amniotic fluid, etc.
An important organic fluid passing through the vaginal canal and exiting through the vaginal orifice is blood, either as a result of physiological conditions such as the menstrual period or as a result of pathological conditions such as cervical or endometrial carcinoma or as a result of dysfunctional uterine bleeding. The various inconveniences to women resulting from the occurrence of physiological bleeding occurring during the menstrual period have prompted attempts to regulate or control the outflow of menstrual bleeding according to the women personal and social needs. For the purpose of controlling the outflow of menstrual blood, vaginal tampons were introduced a few decades ago. Vaginal tampons are common catamenial devices made of absorbing material and insertable into the vagina by the female user. Due to their absorbing material, tampons, once inserted into the vagina, begin to absorb upon contact the blood they meet, which outflows from the cervical canal into the vagina, and function as reservoirs aiming at delaying exit of the blood from the vaginal orifice conceivably until they become saturated with blood and, in so doing, they exert a regulatory effect on the outflow of menstrual bleeding to meet women's' needs or preferences.
However, regardless of their absorbency capabilities, tampons, for various reasons, are known to allow leakage of menstrual blood at rather unpredictable time or shortly after insertion, falling short of providing the regulatory effect which is the very reason for their use. No known tampon is capable of preventing leakage of blood from the vaginal orifice, regardless of shape, size, intravaginal resting site, absorbency capabilities of the material or materials of which they are made of, etc. Blood may leak from the vaginal orifice because the tampon is too early saturated with blood or because the blood flow is disproportionately heavy for the absorbency capabilities of the inserted tampon or because the tampon does not provide an adequate sealing with the vaginal walls or orifice or for all the above reasons variously combined.
Despite the use of tampons, therefore, leakage of blood from the vaginal orifice is almost the rule during the days of the vaginal bleeding and its occurrence may result in a great deal of annoyance and inconvenience to the woman: leakage indeed actually defeats the main purpose for which tampons are used.
Prior art deals with the problem of leakage of the tampons, some inventions by providing additional blood reservoirs to the tampons, some others by increasing the tampons absorbing capabilities by the means of improved absorbing material, others by using absorbing pads to apply in correspondence of the vaginal orifice to capture the blood escaped from the tampon. In all such cases, main object of the prior art is rather to minimize and possibly delay the outflow of blood, rather than reliably preventing the leakage of blood until it is the appropriate time for the woman, as determined by the woman rather than by her endometrium, to permit exit of the menstrual blood from the vaginal orifice.
The invention by R. Poncy et Al., U. S. Pat. No. 4,020,841, discloses a catamenial tampon comprising an elongated core of conventional highly absorbent fibrous material enclosed along its sides and posterior end by a sheath of nonabsorbent, resilient and thus compressible foam material whereby the storage capacity of the absorbent core is unaffected by compressive forces due to muscular activity or withdrawal of the tampon, such compression being accommodated fully by said nonabsorbent outer sheath.
The catamenian device by R. Poncy is therefore a tampon where the absorbing material, an elongated core, is nested almost entirely in a cup-like sheath which exposes only the anterior end of the tampon. Said cup-like sheath acts also as a cushion interposed between the tampon and the vaginal walls.
One of the most significant drawbacks of Poncy's device is the fact that, in order to expand sufficiently to extend from wall to wall of a vagina to effect sealing and prevent leakage of blood, the sheath of resilient material which envelops the tampon along its sides needs to be conveniently thick. Such a need for sufficient thickness of the sheath necessarily requires that the tampon core nested within the sheath be constructed of a significant smaller diameter than any conventional tampon made to fit the vaginal canal. In terms of volume, the volume of the absorbing core proposed by Poncy is necessarily a small fraction of the volume of any conventional tampon. Since the volume of a tampon is a key factor influencing its absorbing capacity, the absorbing capacity of the tampon proposed by Poncy is necessarily a small fraction of the absorbing capacity of any conventional tampon. Such a drawback, combined with the significantly reduced exposure of the absorbing surface of the tampon, confined to the anterior end of the tampon, leads to the great inconvenience of defeating the fundamental function of a tampon, which is of delaying the menstrual flow as a result of its absorption of blood. Due to its reduced absorbing capacity, the Poncy's catamenian tampon, therefore, has the very undesirable disadvantage of requiring more frequent replacements, as compared to the number of replacements required with a conventional tampon made of the same material because of the restriction of volume expansion undergone by Poncy's tampon due to the presence of the resilient material surrounding the actual tampon core, or, conversely, Poncy's tampon has the inconvenience of causing the inconvenience of gushing of blood upon removal of the device, if the device is left in place longer than allowed by its absorbing capacity.
Of course, a tampon requiring to be frequently replaced loses greatly or entirely its usefulness.
It is obvious, therefore, that, in order to attain certain advantages over the conventional tampons, the Poncy's device inevitably belittles the most essential function of a tampon, i.e. its absorbing capacity.
In addition to significantly impairing the capacity of absorption of a tampon, the arrangement of the resilient material all around the tampon, as disclosed by Poncy et Al., also affects the overall expandability of the resilient material, because the resilient material in Poncy's disclosure does not extend full thickness from wall to wall of the vagina but is significantly reduced in thickness due to the intermission of a substantially non-compressible tampon: given the wide range of anatomical variability in vaginal size, such restriction in expandability may result with less than optimal vaginal sealing and may result with poor blood leakage prevention.
The surrounding of the tampon by the sheath of resilient material, particularly along the sides of the tampon, as disclosed by Poncy, is not preferential nor exemplificatory in Poncy's patent, but it clearly represents the very essence of Poncy's invention, being the only arrangement conceivably possible to achieve all the objectives of Poncy invention. In addition to the objective of preventing blood leakage, the sheath surrounding the tampon obviates the apparent problem of susceptibility to compression of conventional tampons, which, according to the inventors of said device, is a reason for reduction of the effectiveness of the tampon to retain or store the menstrual fluids, inasmuch compression of the tampon could result in the discharge of accumulated fluids both when the tampon is compressed directly such as during withdrawal or indirectly due to the increase in intravaginal pressure caused by the most common of body movements. Also the objective of obviating to the irritation of the vaginal mucosa resulting from frequent insertion and withdrawal of tampons during periods of heavy menses flow can only be attained by a sheath enveloping the tampon core along its sides. A sheath enveloping the tampon core along its sides is, according to its inventors, also essential to obviate to the chafing which may occur during periods of light menses flow because of the tendency of the tampon to absorb whatever small amount of liquids are present on the vaginal walls thereby generating excess friction between the tampon and the vaginal walls.
Zadini et At. describes in their patent application Ser. No. 08/391,342 an inflatable intravaginal device for prevention of blood leakage from the vagina orifice. Such a device expands by inflation not by resiliency.